Evaluation and validation of computed virtual chromoendoscopy in early gastric cancer

BackgroundThe Flexible spectral Imaging Color Enhancement (FICE) system estimates the spectrum reflectance from a white-light endoscopic image and reconstitutes a color image from the wavelength, including useful information about the GI tract. The aim of this study was to investigate the usefulness of FICE with a specific wavelength in the assessment of early gastric cancers (EGCs), and the relationship between the FICE visualization and blood vessels.DesignA retrospective study.SettingDepartment of Endoscopy, Hiroshima University, Hiroshima, Japan.Patients and Main Outcome MeasurementsThe study subjects consisted of 100 patients with EGCs (78 differentiated, 22 undifferentiated) who underwent an endoscopic or surgical resection. We analyzed the wavelengths to generate the maximum difference of the spectral reflectance between the normal gastric mucosa and the EGCs. We observed the same visual field first with white-light endoscopy and then with the FICE system. Then, we scored the demarcation of color between the cancer and the normal mucosa of white-light endoscopic observation and FICE observation, each without magnification. We examined the relationship between the score of the FICE image and the section of the vascular space.ResultsThe wavelength that generated the maximum difference in the tissue was 530 nm. The score of the FICE observation improved in 46 cases (46%), was unchanged in 54 cases (54%), and decreased in no cases (0%). There was a correlation between the score of the FICE images and the section of the vascular spaces.ConclusionsThe FICE observation demonstrated that setting the wavelength at 530 nm resulted in an improvement in the visualization of the EGCs. It is thought that the FICE system is noninvasive and may more easily detect EGC without dye during both routine and detailed examinations.